Alternating current switching device



Oct. 13, 1953 G. c. HARTLEY ETAL 2,655,505

' ALTERNATING CURRENT SWITCHING DEVICE Filed Nov. 15, 1951 2Sheets-Sheet l F/GZ' ln/ef A g 1 iii: 11: i R? 8 E I W ORC/ n [$333 ,2War/v Outlet Du /2L2 Out/at N Inventor G.C-HA RTLE Y F. H. B RAY GHHOUGHBy I flan M44 Attorney Oct. 13, 1953 c, H Y ETAL 2,655,605

ALTERNATING CURRENT SWITCHING DEVICE Filed Nov. 15, 1951 2 Sheets-Sheet2 as .%n i:

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Ouf/et N W Inventor CLCHARTLEY" FH-BRAY- CzHHOUGH ttorney Patented Oct.13, 1953 UNI-TED STATES Q FFICE ALTERNATING; CURRENT. SWITCHING DEVICE.

ApplicationNovember 15, 1951, Serial No. 255,435; InreatBr tain mberL6,. .950..

6 Claims. I (Cl. 307-938)- This invention comprises means forestablishing alternating current transmission connections;

between an inlet and to an outl'etj or any one of. plurality of outletsby electronicmeans.

According to the; invention an alternatingcurrent switching devicecomprises, in combination a, gas discharge tube having a priminggapand/two or more'mutually independent gaps and in which discharge acrosssaid priming gap is sufficient to cause discharge across said' othergaps, two-wire transmission circuits connected respectively to;theianod'e s' and to the cathodes of a pair ofjsaid mutually-independentgaps and providedwith D. C; connectionsformaintaining the dischargfi viasaidj'mutually independent gaps when the priming gap discharge isremoved, so

that said mutually independent gaps will pass alternating current;between said transmission circuits.

Also according tothe invention, an alternating.

current switching device comprises, in, combina' tion, a cold cathodegas discharge tube which has three or more pairs of anode-cathode gaps,one of which isa priming gap. and the others are workinggaps, and inwhichdischarge across said priming gapis. sufiicient to cause dischargeacross said working gaps, two pairs of A. C. terminals, two transmissionbridges which are each connected between a corresponding pair of A. C.terminals, and respectively the anodes and the cathodes of a pair ofworking gaps of said tube, and D. C. discharge maintenance currentterminals connected to said transmission bridges whereby D. C. dischargemaintaining potential is connected across said gaps in parallel, whileA. C. currents are passed via said gaps in series.

The invention will be described with reference to certain embodimentsshown in the accompanying drawings in which:

Fig. 1 illustrates the basic principle and shows a single switchingdevice for connecting an input or inlet A to an output or outlet B;

Fig. 2 shows an extension of the principle whereby means are providedfor connecting an inlet to any of the "n outlets, each of which issimilar to outlet B, Fig. 1 and to all of which the inlet is connectedin multiple;

Fig. 3 shows a further extension in which any one of a number of inlets(only two are shown) can obtain connection to any one of a number ofoutlets I to N.

The switching device, Fig. 1, consists of a gasfilled tube comprising acontrol gap CG and two mutually-independent working gaps GI and G2. Atwo-wire inlet A is connected via a repeating frequencytransmissionbridge, e. g.

Whenpotentiais are applied to X and 2. coilIBQto;the anod'esoi G1,,G2';while the;cor responding cathodes are connected via repeating coil ORGto out'let' B; may be replaced by any other usual form 01 voice theStone r d e Y th'epriminggap discharges, ionisation occurs, and thetubesustains across the working gaps GI andjGZ' when the potentials on X andY are removedfby virtue of +oe D. C; potentials connected'in parallelfrom the centre point of coil IRCtothe anodes ofigaps GI, and G2 andearth connected in, parallel'from the centre point of coil GRC to thecathodes of GI and G2. If new a source of V. E. current is applied tothe inlet A then V. current willbe passed through the gaps GE and G2 tothe outlet or output B. Alternatively, if theN. F. source is applied tothe out- DL UB, current will-be passedthrough the ionised gaps totheinputA. Fig. 1 thus illustrates means for the, connection of.conversation. between two two wire voice channels, in auto telephoneexchange system.

In Fig.2,asing1e repeating coil IR-C is connected. to the inletA. and inmultiple to the anode of. the working; gaps of a group of N gastubes.

Theanodes of the priming gaps are connected in multiple totaj singlelnlet wire The cathodes of the working gapsof each tube are connectedrespectively to correspondin individual repeating coils ORCI ORCN. whilethe priming gap cathodes are connected to individual outlet wires YI YN.To select, say an outlet 2, a potential is applied to wires X and Y2causing ionisation to occur in the second tube. On removal of thesepotentials the tube sustains and a V. F. transmission path isestablished between the inlet A and outlet 2.

In Fig. 3, several arrays of tubes, each array similar to that of Fig.2, have different inlets I, 2 each inlet being multipled to the anodepairs of all tubes of one array. The outlets I, 2 N are multipled eachto the cathode pairs of the corresponding tubes (e. g. I I, 2|) of allthe arrays.

The priming anodes of each horizontal array of tubes are multipled to acommon priming inlet; XI, X2,

The priming cathodes of each vertical array of tubes are multipled to acommon priming outlet Yl, Y2... YN.

By operating the corresponding control gap, connection can beestablished between any inlet and any outlet, e. g. by applying thecorrect potentials to control wires XI and Y2 connection Therepeatingcoils can be established from inlet 5 to outlet 2 via thesecond tube in the top horizontal array.

Each switching element is shown as having a control gap for initiatingionisation and two independent gaps for passing V. F. intelligence.There is no limitation to the number of these independent gaps so thatin addition to two gaps used for passing V. F. other gaps may be usedfor miscellaneous control purposes. Four-wire switching could. also beprovided in which case two pairs of speech gaps would be provided ineach tube plus any additional gaps required for control purposes. Anumber of such switching elements, each comprising a priming gap and aplurality of working gaps, may also be housed in the same envelope,ionisation being limited to one element without efiecting others.

While the principles of the invention have been described above inconnection with specific embodiments and particular modificationsthereof, it is to be clearly understood that this description is madeonly by way of example and not as a limitation on the scope of theinvention.

What we claim is:

1. An alternating current switching device comprising, in combination, agas discharge tube having a priming gap and two or more mutuallyindependent gaps and in which discharge across said priming gap issufficient to cause discharge across said other gaps, two-wiretransmission circuits connected respectively to anodes and to thecathodes of a pair of said mutually independent gaps and provided withD. C. connections for maintaining the discharge via said mutuallyindependent gaps when the priming gap discharge is removed, so that saidmutually independent gaps will pass alternating current between saidtransmission circuits.

2. An alternating current switching device as claimed in claim 1 and inwhich said transmission circuits each includes a transmission bridge viawhich said D. C. discharge-maintaining connections are made via saidpair of gaps in parallel.

3. An alternating current switching device comprising, in combination, acold cathode gap discharge tube which has three or more pairs ofanode-cathode gaps, one of which is a priming gap and the others areworking gaps, and in which discharge across said priming gap issufficient to cause discharge across said working gaps. two pairs of A.C. terminals, two transmission bridges which are each connected betweena corresponding pair of A. C. terminals, and respectively the anodes andthe cathodes of a pair of working gaps of said tube, and D. C. dischargemaintenance current terminals connected to said transmission bridgeswhereby D. C. discharge maintaining potential is connected across saidgaps in parallel while A. C. currents are passed via said gaps inseries.

4. A switching device as claimed in claim 3 and comprising a pluralityof said gas discharge tubes, and pairs of working gaps of all said tubesconnected at one side in multiple to a single transmission bridge and atthe other side to in dividual transmission bridges, a single multipledconnection to said one side of the priming gaps of all said tubes, andindividual connections to said other sides of said priming gaps.

5. A switching device as claimed in claim 4 and comprising a pluralityof groups of gas discharge tubes, each group comprising the same numberof tubes, a first set of transmission bridges equal in number to thenumber of tubes in each group, and each connected in multiple to theanode (or cathode) pairs of a set of tubes comprising a single tube pergroup having the same positions in the groups, e. g. all the first tubesof the groups, a single multipled priming connection to the anodes (orcathodes) of the priming gaps of each of the said sets of tubes, 2.second set of transmission bridges equal in number to the number ofgroups and each connected in multiple to the cathode (or anode) pairs ofall the tubes of the one'group, and a single multipled primingconnection to the cathodes (or anodes) of the priming gaps of each ofsaid groups of tubes.

6. A switching device as claimed in claim 3, and comprising two pairs ofworking gaps per tube and corresponding provision of transmissionbridges and connections whereby four-wire transmission is provided.

GEORGE CLIFFORD HARTLEY. FREDERICK HARRY BRAY. GEORGE HUBERT HOUGH.

No references cited.

